Urban Meyer, the Ohio State football coach, said Friday afternoon that he had “followed proper reporting protocols and procedures” after learning of a 2015 incident in which a longtime assistant, Zach Smith, was accused of domestic abuse.

In an eight-paragraph statement released on Twitter two days after Ohio State placed him on administrative leave pending an investigation, Meyer also said he had failed to be “clear, compassionate and, most of all, completely accurate” when he said last week that he had just become aware of the incident.

Confronted with questions about the 2015 incident at a news conference for the Big Ten Conference on July 24, Meyer said he had learned of the accusations only the night before. In Friday’s statement, Meyer said he had been “unprepared to discuss these sensitive personnel issues with the media, and I apologize for how I handled those questions.”

In an ESPN interview later on Friday, Smith denied ever having committed domestic abuse. He also said that Meyer had confronted him about the 2015 allegation and that Meyer had heard about it from Ohio State’s athletic director, Gene Smith.

“He looked me and he said, ‘I swear to God, Zach, if I find out you hit her, you’re done, you’re fired,’” Smith said of Meyer.

The independent journalist Brett McMurphy published an initial story about the 2015 allegations on July 23 and then published photographs this week that showed Courtney Smith, who is now divorced from Zach Smith, bruised and bloodied. She said the pictures had been taken after assaults in 2014 and 2015 by her then-husband, and she told McMurphy she had shared the images with several other coaches’ wives.

Text messages also reported by McMurphy on Wednesday show that Meyer’s wife and the wives of other assistants knew about the 2015 incident and suggest that Meyer then confronted Smith about it, as Smith seemed to confirm in the ESPN interview.

Smith contended that any marks on Courtney Smith after the 2015 incident were the product of “defensive movements to remove myself from the situation” and said that he had told the police as much at the time.

A lawyer identified in recent court papers as representing Courtney Smith did not immediately respond to an emailed request for comment.

The statement from Meyer, one of college football’s most successful and best-paid coaches, raised new questions even as it answered others. It is still not clear exactly when he learned of the 2015 incident, when he reported it and which protocols he followed.

Meyer kept Smith on his staff, as wide receivers coach and recruiting coordinator, for years after the 2015 incident. Meyer fired Smith last week after McMurphy’s initial reporting, which included information on a protection order and a misdemeanor trespassing charge against Smith from this year. Smith is the grandson of Earle Bruce, a former Ohio State coach and a mentor of Meyer’s, and he played for Meyer at Bowling Green and was his graduate assistant at Florida.

It is also not clear who else in the athletic department knew about the incident, and what their understanding of it was. A university spokesman did not immediately reply to a request for comment from Gene Smith.

Meyer promised to cooperate with an inquiry the university has ordered into the matter. The investigating commission includes university trustees and members who are independent of the university.

The Meyer scandal is one in a series of controversies that Ohio State has been dealing with in recent weeks. The university announced last month that more than 100 former students had said that a former team doctor sexually abused them over a period from the late 1970s to the mid-1990s. Also, a former member of the Ohio State University Diving Club has said in a lawsuit that an assistant diving coach had an inappropriate sexual relationship with her when she was 16 and that the university had failed to provide an adequate way to report it.

At a news conference last week, Meyer acknowledged he had known about a 2009 incident in which Smith, then a member of his staff at Florida, was arrested on accusations of domestic abuse. Smith was not prosecuted. Meyer said at the news conference that he and his wife, Shelley, had tried to counsel the young couple then.

A version of this article appears in print on , on Page D2 of the New York edition with the headline: Ohio State’s Meyer Says He Followed Procedures on Reporting Abuse. Order Reprints | Today’s Paper | Subscribe